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Dynamic Distribution of Spindlin in Nucleoli, Nucleoplasm and Spindle from Primary Oocytes to Mature Eggs and its Critical Function for Oocytes-to-Embryo Transition in Gibel Carp

 

On October 1, the Journal of Experimental Zoology Part A: Ecological Genetics and Physiology published the paper "Dynamic Distribution of Spindlin in Nucleoli, Nucleoplasm and Spindle from Primary Oocytes to Mature Eggs and its Critical Function for Oocytes-to-Embryo Transition in Gibel Carp”, completed by GUI Jianfang, Professor of Institute of Hydrobiology, Chinese Academy of Sciences (IHB), LI Zhi, technician of IHB and IHB doctoral student SUN Min, and highlighted this research finding in its Features column:

"Mature oocytes contain stockpiles of ‘maternal-effect factors’ that drive the earliest stages of embryonic development. Several studies have suggested that spindlin is one such factor, and Sun et al. have used the gibel carp (Carassius auratus gibelio) as a model to characterize its involvement in the oocyte-to-embryo transition (pp461-473). They used antibodies to assess ovarian expression of gibel carp spindlin (CagSpin), and observed specific localization of this protein within primary oocyte nucleoli.

As oocytes matured, CagSpin labeling revealed a dramatic increase in the number of nucleoli from 2-10 to as many as 1,000; with the onset of vitellogenesis, this protein rapidly redistributed throughout the nucleoplasm, ultimately co-localizing with the spindle fibers in the mature oocyte. CagSpin levels diminished rapidly post-fertilization, with no protein detectable by the eight-cell stage. Nevertheless, it appears to play a vital part in early embryogenesis, and fertilized eggs injected with anti-CagSpin generally exhibited fatal defects in spindle assembly, chromosomal segregation and cleavage. Collectively, these data suggest the spindlin is a true maternal-effect factor, with a major role in the events immediately following fertilization.” (by Michael Eisenstein) 

The research was funded by the National Key Basic Research Program (also called 973 Program), National Technology System for Conventional Freshwater Fish Industries etc.